scholarly journals Fácies orgânica da Formação La Luna, Bacia do Valle Superior Del Magdalena, Colômbia: implicações para a geração de petróleo e caracterização paleoambiental

2007 ◽  
Vol 30 (2) ◽  
pp. 65-81
Author(s):  
Juliana Andrade Iemini ◽  
João Graciano Mendonça Filho ◽  
Felix Thadeu Teixeira Gonçalves ◽  
Taíssa Rêgo Menezes
Keyword(s):  
Upper Cretaceous ◽  
Thermal Evolution ◽  
Organic Geochemistry ◽  
Maturation Stage ◽  
Hydrocarbon Production ◽  
Thermal Maturation ◽  
Oil Reserves ◽  
Organic Facies ◽  
Oil Generation ◽  
La Luna

Upper Cretaceous pelitic rocks generate most of the oil reserves in Colombia. In Del Magdalena Upper Valley (MUV), the existence of good quality outcrops and thermal evolution levels that vary from immaturity to the end of the oil generation "window" makes it one of the most appropriate regions for the study of primary migration and generation of oil in Upper Cretaceous. The main objectives of this work were to study the organic facies of La Luna Formation in an outcrop section called Riacho Bambuca (Bambuca Creek), determine the oil generation potential and characterize the paleoenvironment. For this research, 24 samples were used in palynofacies analysis (characterization of the kerogen components assembly) and in organic geochemistry analysis (Total Organic Carbon - TOC analysis and Rock-Eval pyrolysis, provided by Colombia Oil Institute - ECOPETROL). The palynofacies analysis included the use of microscopy techniques (transmitted white light and incident blue light). Furthermore, a Spore Coloration Index (SCI) analysis was made in order to determine the thermal maturation stage. The studied material was composed mainly of an amorphous organic substance, with its fluorescent coloration varying from yellow to bright orange. The palynomorph group is represented by spore morph and dinoflagellate cysts. The ligneous material are present in very low percentages; they are mainly opaque phytoclasts. The results of geochemical analysis showed TOC contents ranging from medium to high, excellent potential for the generation of hydrocarbons (PG >; 4 mg HC/g of rock), hydrogen index ranging from 329 to 589 mg HC/g, and low values of oxygen index, characterizing type II kerogen. The low degree of thermal maturation was determined by Spore Coloration Index values ranging from 2,5 to 3,0, Tmax values below 440ºC and Hydrocarbon Production Index inferior to 0,2. According to the organic facies data, La Luna Formation deposited in a marine environment with facies from disoxic-anoxic distal shelf and suboxic-oxic distal basin; there was kerogen of excellent quality, and its quantity was adequate for the generation of oil.

scholarly journals Geochemical Considerations from the Carboniferous Unconventional Petroleum System of SW Iberia

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 811
Author(s):  
Gabriel A. Barberes ◽  
Rui Pena dos Reis ◽  
Nuno L. Pimentel ◽  
André L. D. Spigolon ◽  
Paulo E. Fonseca ◽  
...  
Keyword(s):  
Random Distribution ◽  
Thermal Evolution ◽  
Organic Geochemistry ◽  
Black Shales ◽  
Petroleum System ◽  
Point Of View ◽  
Gas Reservoir ◽  
Thermal Maturation ◽  
Petrographic Analyses ◽  
Rock Eval

The Baixo Alentejo Flysch Group (BAFG) is an important stratigraphic unit that covers over half of the South Portuguese Zone (SPZ) depositional area, and it is composed by three main tectono-stratigraphic units: the Mértola, Mira, and Brejeira formations. All of these formations contain significant thicknesses of black shales and have several wide areas with 0.81 wt.%, 0.91 wt.%, and 0.72 wt.% average total organic carbon (TOC) (respectively) and thermal maturation values within gas zones (overmature). This paper is considering new data from classical methods of organic geochemistry characterization, such as TOC, Rock–Eval pyrolysis, and organic petrography, to evaluate the unconventional petroleum system from the SPZ. A total of 53 samples were collected. From the stratigraphical point of view, TOC values seem to have a random distribution. The Rock–Eval parameters point out high thermal maturation compatible with gas window (overmature zone). The samples are dominated by gas-prone extremely hydrogen-depleted type III/IV kerogen, which no longer has the potential to generate and expel hydrocarbons. The petrographic analyses positioned the thermal evolution of these samples into the end of catagenesis to metagenesis (wet to dry gas zone), with values predominantly higher than 2 %Ro (dry gas zone). The presence of thermogenic hydrocarbon fluids characterized by previous papers indicate that the BAFG from SPZ represents a senile unconventional petroleum system, working nowadays basically as a gas reservoir.

Regional Sequence Stratigraphy of the Upper Cretaceous La Luna Formation in the Magdalena Valley Basin, Colombia.

2014 ◽  
Author(s):  
Henry A. Galvis-Portilla ◽  
I. Camilo Higuera-Diaz ◽  
Sandra Cespedes ◽  
Cesar Ivan Ballesteros ◽  
Silvia Forero ◽  
...  
Keyword(s):  
Sequence Stratigraphy ◽  
Upper Cretaceous ◽  
La Luna

scholarly journals The Cogollo Group and the oceanic anoxic events 1a and 1b, Maracaibo basin, Venezuela

2015 ◽  
Vol 45 (suppl 1) ◽  
pp. 41-61 ◽  
Author(s):  
José Alejandro Méndez Dot ◽  
José Méndez Baamonde ◽  
Dayana Reyes ◽  
Rommel Whilchy
Keyword(s):  
Source Rock ◽  
Organic Geochemistry ◽  
Sedimentary Facies ◽  
Source Rocks ◽  
Maracaibo Basin ◽  
Pelagic Environment ◽  
Anoxic Events ◽  
Anoxic Environment ◽  
Platform System ◽  
La Luna

ABSTRACTCarbonates of Cogollo Group (Apón, Lisure and Maraca formations) constitute the broader calcareous platform system originated during Aptian and Albian of Cretaceous in north-western South America, Maracaibo Basin, Venezuela. On the shallow shelf, a variety of calcareous sedimentary facies were deposited during marine transgressive and regressive cycles. Some of them developed porosity and constitute important hydrocarbon reservoirs. Due to some major marine transgressions, from early Aptian, the anoxic environment and characteristic facies of a pelagic environment moved from the outer slope and basin to the shallow shelf, during specific time intervals, favouring the sedimentation of organic matter-rich facies, which correspond to the oceanic anoxic events (OAEs) 1a and 1b. The source rock of Machiques Member (Apón Formation) was deposited during early Aptian OAE 1a (~ 120 Ma). The source rock of Piché Member, located at the top of the Apón Formation, was deposited during late Aptian OAE 1b (~ 113 Ma). Finally, La Luna Formation, from Cenomanian, that covers the OAE 2 (~ 93 Ma), represents the most important source rock in the Maracaibo Basin. In this way and based on sedimentological and organic geochemistry results from the determinations performed on 247 samples belonging to six cores in the Maracaibo Basin, we propose these two organic-rich levels, deposited on the shallow shelf of the Cogollo Group, as "effective source rocks", additional to La Luna Formation, with oil migration in relatively small distances to the porosity facies.

ORGANIC GEOCHEMISTRY OF CRUDE OILS AND UPPER CRETACEOUS SOURCE ROCKS FROM CONCESSION 11, WEST SIRTE BASIN, LIBYA

2016 ◽  
Vol 39 (4) ◽  
pp. 393-413 ◽  
Author(s):  
W. Sh. El Diasty ◽  
S. Y. El Beialy ◽  
K. E. Peters ◽  
H. El Atfy ◽  
A. M. Gheith ◽  
...  
Keyword(s):  
Upper Cretaceous ◽  
Organic Geochemistry ◽  
Source Rocks ◽  
Crude Oils ◽  
Sirte Basin

Allochthonous salt sheet growth: Thermal implications for source rock maturation in the deepwater Burgos Basin and Perdido Fold Belt, Mexico

2017 ◽  
Vol 5 (1) ◽  
pp. T11-T21 ◽  
Author(s):  
Ian Davison ◽  
Tiago Abreu Cunha
Keyword(s):  
Source Rock ◽  
Thermal Evolution ◽  
Physical Parameters ◽  
Fold Belt ◽  
Petroleum Systems ◽  
Salt Level ◽  
Transient Heat Flow ◽  
Oil Generation ◽  
Flow Effects ◽  
Base Salt

A better understanding of suballochthonous salt petroleum systems can be achieved by thermal modeling a series of vertical pseudowell profiles that are positioned along ramps and flats identified at the base salt level. This allows the changing 2D shape of the highly conductive salt to be taken into account and assesses the physical parameters that control the thermal evolution. A case study of a typical cross section through the Burgos Basin and Perdido Fold Belt is analyzed in an area of very active oil exploration in northern Mexico. Numerical experiments indicated how the extrusion of salt cools the underlying basin and significantly prolongs the period of Tithonian source rock maturity. The rapid extrusion of thick allochthonous salt sheets, and the associated transient heat flow effects, can also cause peaks in oil generation, in places postdating the trap formation during the Oligo-Miocene folding event. The principal Tithonian source rock is predicted to have remained in the oil window since Paleogene times, despite being buried to present-day depths of approximately 8 km subsea. This upgrades the oil potential of some of the subsalt areas that are currently on offer in the CNH-R01-L04/2015 Mexico deepwater Licensing Round.

Évolution thermique et potentiel pétroligène par l'étude des kérogènes, des extraits organiques, des gaz adsorbés, des argiles, du sondage Karlsefni H-13 (offshore Labrador, Canada)

1981 ◽  
Vol 18 (12) ◽  
pp. 1856-1877 ◽  
Author(s):  
Y. Héroux ◽  
R. Bertrand ◽  
A. Chagnon ◽  
J. Connan ◽  
J-L. Pittion ◽  
...  
Keyword(s):  
Clay Mineralogy ◽  
Maturation Stage ◽  
Type Ii ◽  
Thermal Maturation ◽  
Wet Gas ◽  
Physico Chemical ◽  
Organic Extracts ◽  
Microscopic Studies ◽  
Maturation Stages ◽  
Analytical Parameter

The Tertiary sequence of the Labrador offshore (Karlsefni H-13 well) is formed by clayey–detrital lithologies for which thermal maturation and oil potential have been established.The kerogen of this sequence is ligneous (type III) but shows a slight tendancy towards a more sapropelic (type II) character between 2000 and 3300 m. The amorphogen, abundant throughout the borehole, is partly derived from the destruction of woody matter. The sapropelic trend of the kerogen corresponds to an increase of the organic carbon and amorphogen content. In this sequence, the best oil potential (fair to good) would be offered by the lithologies between 2000 and 3300 m, if the appropriate catagenetic zone had been reached.The amount of gas produced with respect to oil, in the 2000–3300 m interval, is a function of the thermal maturation. The oil window maturation stage (potential oil window (POW)) is reached at 3750 m. Two thermal maturation stages occurred before the POW: an upper dry gas (methane) stage (2160–2520 m) and an upper wet gas (condensate) stage (2520–3750 m). A biogenic gas zone (650–765 m) also occurs at the top of the unproductive immature zone. More than one analytical parameter must be used to differentiate these diagenetic stages. These parameters come from the physico-chemical and microscopic studies of the kerogens, organic extracts, adsorbed gases, and clay mineralogy.

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